title: Accurate and early diagnosis of orthopedic device-related infection by microbial heat production and sonication.
abstract: Proper and rapid diagnosis of orthopedic device-related infection is important for successful treatment. Sonication has been shown to improve the diagnostic performance. We hypothesized that the combination of sonication with a novel method called microcalorimetry will further improve and accelerate the diagnosis of implant infection. We prospectively included 39 consecutive patients (mean age 59 years, 62% males) at our institution from whom 29 orthopedic prostheses and 10 osteosynthesis material were explanted. The explanted device was sonicated. The resulting sonication fluid was analyzed using microcalorimetry. Using standardized criteria to define orthopedic device-related infection, 12 cases (31%) were defined as infected. In all, positive periprosthetic tissue cultures were found. The sensitivity and specificity of microcalorimetry of sonication fluid were 100% and 97%, respectively. Mean time to detection, defined as time to reach a rising heat flow signal of 20 µW measured after equilibiration needed to get accurate measurement, was 10.9 h. In summary, microcalorimetry of sonication fluid is a reliable and a fast method in detecting the presence of microorganisms in orthopedic device-related infection.
authors.affiliation: Orthopedic Septic Surgical Unit, Department of the Locomotor Apparatus and Department of Surgery and Anesthesiology, l, University of Lausanne, Lausanne University Hospital, BH-10 Rue du Bugnon 46, 1011, Lausanne, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Borens
authors.forename: Erlangga
authors.initials: E
authors.lastname: Yusuf
authors.forename: Julia
authors.initials: J
authors.lastname: Steinrücken
authors.forename: Andrej
authors.initials: A
authors.lastname: Trampuz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000378:metabolism*; D001431:Bacteriological Techniques / Q000379:methods*; D002151:Calorimetry; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009983:Orthopedic Equipment / Q000009:adverse effects*; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology; D013010:Sonication; D022722:Thermogenesis
keywords: implanted orthopedic device; infection; microcalorimetry; sonication